Attachment-plug cap



y 14, 1929- A. s. SPIDEL ATTACHMENT PLUG CAP Filed June 1928 fltoz, Spide/ I ammq Patented May 14, 1929,

UNITED STATES 1,712,133 PATENT OFFICE.

ARTHUR S. SPIDEL, OF BREWSTER, OHTO, A SSIGNOR 0F ONE-HALF TO B. A. HAM-ILTON, OF NAVARRE, OHIO.

ATTACHMENT -'.PLUG CAP.

Application filed June 2, 1928. Serial No. 282,357.

My invention relates to the caps of separable attachment plugs forelectric cables and the like, and more particularly to caps including aninneraoontact blade mounting member of relatively rigid insulatingmaterial, and an outer protective covering therefor of relativelyresilient material,

- whereby the cap may be dropped without breaking. I

Such plug caps as ordinarily made 1nclude for the blade mounting member,a rigid disk of insulating material, which may be bakelite, andwhich isprovided with a relatively large central opening through which the cordis inserted for attachment to the binding screws of the contact bladebase plates.

The usual resilient cover for the disk is made of soft rubber and is inthe shape of a dome having a central aperture at its crown forreceivingthe cord, and is internally secured near its base to the periphery ofthe disk. A

The central openings in the disks of attachment plug caps thusconstructed, very materially weaken the same. Moreover such plug caps,while being adapted for the proper connection of the cable cords byleading or snubbing' the cords around the contact blades and passingthem over the top of the contact blade base plates to the bindingscrews, are also adapted for improper connection of the cable cords withthe contact blades by leading the cords directly to the binding screwsfrom the center of the cap without snubbing the cords around the contactblades and without passing them over the top of the contact blade baseplates in the proper manner.

It is desirable to snub the cords around the contact blades and leadthem over the top of the contact blade base plates to the binding screwsto avoid short circuits, and to minimize the strain on the bindingscrews caused by applying a tension to the cable attached to the plugcap.

Accordingly the objects of the present improvements include theprovision of an at tachment plug cap including a rigid blade mountingmember and a resilient dome cover therefor and in which the blademounting member is in a form which is structurally much stronger thanthe usual apertured disk, and is also provided with cord guide memberswhich will permit the attachment of the cable cords to the contactblades of the plugs only by the proper method of snubbing vthe cordsabout the contact blades and leading'them over the top of the baseplates to the binding screws.

These and ancillary objects are attained in the present improvements bya construction and arrangement which will be hereinafter set forth indetail and claimed.

Preferred embodiments of the invention are illustrated in theaccompanying drawing formingpart hereof, in which Figure 1 is a bladeend view of one em bodiment of the improved plug cap;

Fig. 2, a vertical cross section thereof as on line 2-2, Fig. 1;

Fig. 3, a detachedsectional view of the improved blade mounting membertherefor, as on line 3+3, Fig. 4;

Fig. 4, an elevation view thereof as in the direction of the arrows4-4:, Fig. 3; and

Fig. 5, a View similar to Fig. 2 of a modified embodiment of theimproved plug cap.

Similar numerals refer to similar parts throughout the drawing.

The improved attachment plug cap indicated generally at 10 includes arigid blade mounting member 11, which may be made of insulating materialsuch as bakelite, and which is secured at its periphery 12 in aninternal annular groove 13 of a dome 14, which may be molded of a softrubber or other resilient material.

Contact blades 15 having base plates 16 are secured in a usual mannerupon one side of the blade mounting member 11. The blade mounting member11 may be in the form of a disk 17 having a propeller-like cord guidemember 18 secured at the side of the disk upon which the contact bladesare mounted and which may be preferably molded integral with the disk.

The disk is provided with spaced apertures 19 having formed innersurfaces 20 which merge with surfaces of the cord guide member 18 forforming guideways for the cords 21 of a cable 22. An axial aperture 23is provided in the crown of the dome 1a through which the cords 21extend-before passing through the mounting member apertures 19.

The propeller-like cord guide member 18 is centrally wide enough to actas a spacer for the contact blades 15, and opposite sides of theopposite ends, of the guide member guide member provides an eflicientinsulation between the bare ends 26 of the cords. It is to be understoodthat the particular type of attachment plug ca herein set forth,

and including the soft ru ber dome, is de signed for rough usage wherethe cap is likely to be dropped on a hard floor, when the cap wouldbreak if the dome were made of the usual bakelite material or similarcomposition.

I claim:

1. An attachment plug cap including an outer protective cover ofrelatively resilient material, and an inner contact blade mountingmember of relatively rigid material secured within the cover, themounting member having spaced cord apertures therein.

2. An attachment plug cap including an outer protective cover ofrelatively resilient material, and an inner contact blade mountingmember of relatively rigid material secured within the cover, contactblades including base plates secured on the mounting member, and themounting member havin spaced cord apertures therein, and the corapertures having faces forming guideways for snubbing cord wires aboutthe contact blades and directing them over the base plates.

3. An attachment plu cap including an outer protective cover ofrelatively resilient material, and an inner contact blade mountingmember of relatively rigid material secured within the cover, themounting member having spaced cord apertures therein, and contact bladessecured on the mounting member.

4. An attachment plug cap including an outer protective cover ofrelatively resilient material, and an inner contact blade mountingmember of relatively rigid material secured within the cover, contactblades including base plates and binding means secured on the mountingmember, and the mounting member having spaced cord apertures therein,and the cord apertures havin faces forming guideways for snubbing cordwires about the contact blades and directing them over the base plates.

In testimony that I claim the above, I have hereunto subscribed my name.

ARTHUR S. SPIDEL.

